glacial striations on basalt columns - devils postpile (california)

The top of the columns of Devils Postpile - Columnar Basalt in the Eastern Sierra (California)

A basalt volcanic flow formed hexagonal-shaped columns when it cooled down.­

You can clearly see the parallel grooves showing the erosion caused by debris pushed by the slow-moving ice of the glacier that used to cover this valley.­ Those marks are called glacial striations.­

For more info about this rock formation, go to en.­wikipedia.­org/­wiki/­Devils_­Postpile_­National_­Monument.

california columnar basalt columns devils postpile eastern sierra erosion forest geology glacial polish glacial striations lava flow rock formation trees volcanic
Inyo National Forest, Pacific Crest Trail, California, USA

Lava beds and geothermal features in the Pacific North-West.­

Photos taken in various locations of the Eastern Sierra region, in California.­